7.13 String literals
String literals consist of a series of characters or spaces contained between double quote characters.
The length of a string literal is restricted by the length of the input line.
To include a double quote character or a dollar character
within the string literal, include the character twice as a pair.
For example, you must use
$$ if you require a
$ in the string.
C string escape sequences are also enabled and can be used
within the string, unless
--no_esc is specified.
abc SETS "this string contains only one "" double quote"
def SETS "this string contains only one $$ dollar symbol"